WHEN blue-collar scribe Ben Hamper talks about his "if-the-nuns-could-see-me-now book tour," he describes the culture shock of sitting in a sumptuous Washington hotel restaurant eavesdropping on a woman's patter about "selecting the proper shoe for the proper time and place."The guy who boozed and cruised through his youth with a Dingo boot to the metal of a hot Camaro raises his beefy arms to parenthesize a shrug of disbelief, "Man, they're not on the same planet!" That's for sure. And in a recent interview, the author's discomfort outside his Michigan working-class world was palpable in his constant unconscious shirtpocket-pat for a cigarette, his edge-of-the-chair demeanor, and the marked absence of expletives so integral to the life he depicts in "Rivethead: Tales From the Assembly Line." "It's sort of ironic that I started writing because I had trouble communicating with people, and now that I've written this book I have to go around talking to people in all these strange cities I've never been to," Mr. Hamper says of the string of reporters, and publishing and Hollywood types lining up to see him. This vulnerability - a touching mix of witty intelligence and apparent unhappiness - always seems to come to the rescue just when his wild ways verge on losing the sympathy of his audience. Claiming he doesn't have the attention span to read books, Hamper is informed purely by his own working-class experience and a common man's uncomplicated observations. He reminds you of guys you've known - and liked, in spite of it all. The Rivethead battles the time clock with assembly-line mischief, cynicism, and self-destructive irresponsibility. Yet Hamper is surprised when interviewers are curious, for example, about how it all affects his family, which gets scant mention in his tale, and the General Motors products popping off assembly lines manned by auto workers with the Rivethead's sensibilities. Asked about the quality of the product he was putting out while devising schemes to beat the clock, ennui, and his own personal problems, Hamper testifies that "I bought five straight Camaros." "The rivet line where I worked was probably one of the top two or three highest rated departments in this huge truck factory. And per capita it had more miscreants and drunkos than anywhere. But we all knew where the line was, where not to step over," he says. "The end justifies the means. Who cares about how the cars are built or by who or what condition they're [workers] in as long as [cars] come out right.... All I could do was control the guy who put on the dual-exhaust muffler - that was me. I always did it right, so that's all I can speak for." Don't bother asking him to reconcile his ethics with say, labor union rules, or consumer safety, or Japanese competition. Claiming the just-a-cog-in-the-wheel defense, he declines "political" discussion. Hamper is more tender about his teenage daughter, mentioned once in the book. Here, too, he seems amazed that a reader would wonder about his family. (Surprisingly she has attended Catholic schools all her life despite her dad's scathing attack on the schools his mother slaved to pay for.) He says his family is not in the book because, "I knew it was a depressing, oftentimes vulgar, crazed book. The Rivethead isn't the Ben Hamper, the dad that she [his daughter] knows." The Rivethead, he says, is the guy full of bravado Hamper wanted to be. And it agitates him if anyone makes him more than that. "I'm not the automobile analyst. I'm the Rivethead. This is just Ben Hamper's story. I don't want to be thrust in this role where I'm the mouthpiece for every factory worker." Indeed, he's pretty touchy about false heroes. One of the few of his generation qualified, or inclined, to criticize the Boss (rock star Bruce Springsteen) as a "surrogate songster of the working class ... masquerading as blue collar," he says he'd rather hear the themes Springsteen wails about from the genuine blue-collar talent he's known on the assembly line - sculptors, painters, poets, musicians. Hamper hasn't written since finishing his book a year ago. He doubts GM would have him back. So he considers his occupation to be writing. But, and this is the worrisome thing, he adds, "Now that I'm a writer, that becomes work." And Hamper hates work, characterizing it this way: "Work is for losers."